1. Field of the Invention
The present invention relates to a process for producing an organic photosensitive material preventing blushing and, more specifically, to a process which is effective for the production of a single-layer type organic photosensitive material.
2. Description of the Prior Art
At present, organic photosensitive materials (OPCs) have been extensively used as photosensitive materials for the electrostatic photographic devices. The organic photosensitive materials can be roughly divided into those of the single-layer type in which a single layer obtained by dispersing a charge-generating material (CGM) and a charge-transporting material (CTM) in a binder resin, is formed on a blank tube such as of aluminum, and those in which a layer containing CGM and a layer containing CTM are laminated on a blank tube (usually, the CGM is contained in the lower layer).
These organic photosensitive materials are obtained by preparing a coating solution by dissolving or dispersing the CGM and/or the CTM and a binder resin in an organic solvent, applying the coating solution onto the blank tube by using a blade or by immersion, and drying the coating solution.
Generally, however, the coating solution containing CGM contains an organic solvent in large amounts. Due to the latent heat at the time when the solvent vaporizes after it is applied, therefore, the temperature drops on the surface of the film causing the blushing (whitening) to take place easily. In the case of the organic photosensitive material of the laminated type, the problem is not so serious since the CTM layer is formed on the CGM layer. In the case of the single-layer type organic photosensitive material, however, the blushing takes place on the surface of the photosensitive material and the surface becomes rugged. Therefore, the photosensitive material loses properties such as repetition property when used continuously, resistance against ozone and like properties.